This invention relates to 3-(2-aminoethylthio)-6-amido-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxy lic acids and its pharmaceutically acceptable salt, ester and amide derivatives thereof which are useful as antibiotics and which may be represented by the following generic structural formula (I): ##STR2## wherein R.sup.1 is hydrogen and all acyl radicals known to be effective in the related, bicyclic .beta.-lactam antibiotic art, e.g., the cephalosporins and penicillins. R.sup.1 as acyl is defined representatively below.
This invention also relates to the carboxyl derivatives of I which are antibiotics and which may be represented by the following generic structure (I): ##STR3## wherein X' is oxygen, sulphur or NR' (R'=H or lower alkyl having 1-6 carbon atoms); R.sup.5 is, inter alia, representatively selected from the group consisting of hydrogen, conventional blocking groups such as trialkylsilyl, acyl and the pharmaceutically acceptable salt, ester and amide moieties known in the bicyclic .beta.-lactam antibiotic art; the definition of R.sup.5 is given in greater detail below; R.sup.1 is, in addition to hydrogen, acyl. The term "acyl" is by definition inclusive of the alkanoyls including derivatives and analogues thereof such as thio analogues wherein the carbonyl oxygen is replaced by sulphur; as well as sulphur and phosphorous acyl analogues such as substituted sulfonyl-, sulfinyl-, and sulfenyl- radicals, and substituted P (III and V) radicals such as substituted phosphorous-, phosphoric-, phosphonous- and phosphonic- radicals, respectively. Such acyl radicals of the present invention are further defined below.
This invention also relates to processes for the preparation of such compounds (I); pharmaceutical compositions comprising such compounds; and to methods of treatment comprising administering such compounds and compositions when an antibiotic effect is indicated.
There is a continuing need for new antibiotics. For unfortunately, there is no static effectiveness of any given antibiotic because continued wide scale usage selectively gives rise to resistant strains of pathogens. In addition, the known antibiotics suffer from the disadvantage of being effective only against certain types of microorganisms. Accordingly the search for new antibiotics continues.
Thus, it is an object of the present invention to provide a novel class of antibiotics which are useful in animal and human therapy and in inanimate systems. These antibiotics are active against a broad range of pathogens which representatively include both gram positive bacteria such as S. aureus, Strep. pyogenes, and B. subtilis and gram negative bacteria such as E. coli, Proteus morganii, Serratia, Pseudomonas and Klebsiella. Further objects of this invention are to provide chemical processes for the preparation of such antibiotics and their non-toxic pharmaceutically acceptable salts; pharmaceutical compositions comprising such antibiotics; and to provide methods of treatment comprising administering such antibiotics and compositions when an antibiotic effect is indicated.